Question: $ {-5\cdot \left[ \begin{array}{cc} 1 & 0 \\ -2 & -1 \end{array} \right]=}$
Solution: The Strategy To multiply a matrix by a scalar, we multiply each term of the matrix by the scalar. Multiplying each term $ {\begin{aligned}-5\cdot \left[\begin{array}{rr} {1} & {0} \\ {-2} & {-1} \end{array}\right]&=\left[\begin{array}{rr} -5\cdot{1} & -5\cdot{0} \\ -5\cdot{-2} & -5\cdot{-1} \end{array}\right] \\\\&=\left[\begin{array}{rr} {-5} & {0} \\ {10} & {5} \end{array}\right]\end{aligned}}$ Summary $ {-5\cdot \left[ \begin{array}{cc} 1 & 0 \\ -2 & -1 \end{array} \right]=\left[ \begin{array}{cc} -5 & 0 \\ 10 & 5 \end{array} \right]}$